Is it safe to delete .ptn files

I have recently found that a considerable number of .ptn files have been created in all sorts of folders. I believe that these files have been created by Scansoft Paperport programme. They are all titled "PPThumbs.ptn". I can get the files to open when associating them with Scansoft or any other programme. As I cannot open them, is it safe to delete them. Any suggestions.

why not just delete 'em - - - -but leave them in recycle bin, just in case ?? I had same kind of experience sometime ago with *.prn files - - -these files created when you choose to print to file as opposed to print to, well, printer - - - never got to know how you opened these kinda files and so never got to grips why the option was ther to 'print to file' ..Not much help I guess but am on Tennents Super right now and we did win away today.Good luck.